Diabetic nephropathy (DN) is the major cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD) throughout the world and is the largest single cause of ESRD in the United States, accounting for nearly half of the patients entering dialysis each year, which is a significant financial burden in the country. However, there are only limited numbers of DN animal models, none of which fully recapitulate DN conditions in humans. Two of the best animal DN model are the BTBR ob/ob mouse we generated previously, and eNos mutants. We hypothesized that combining the two mutants may accelerate progression of DN and show more similar phenotypes to human DN patients. DN is reversal uniquely in BTBR ob/ob mice, enabling studies of podocyte regeneration in DN. However, the cellular origin for regenerating podocytes remains unclear. Because genes responsible for BTBR background have not been identified yet, addition of compound mutations to BTBR ob/ob mice requires extensive backcrossing to BTBR background, taking over 3-4 years. In this proposal, we proposed to create compound mutants on the BTBR ob/ob background rapidly using the emerging CRISPR technology. Understanding the molecular and cellular mechanisms for DN progression and reversal would lay the foundation for understanding whether new podocytes formation in adults could be possible for regenerative therapy of kidney diseases including DN.